Business case evaluations for LTE network offloading with cognitive femtocells

Mobile networks are increasingly becoming capacity limited such that more base stations and smaller cells or more spectrum are required to serve the subscribers’ increasing data usage. Among several challenges, the establishment of new base station sites becomes challenging and expensive. This study proposes and analyzes critical aspects of a business case where a mobile operator offloads its mobile LTE network by deploying cognitive femtocells. When aided by a sensor network the cognitive femtocell will be able to use frequencies other than the mobile network and hence increase its power to cover outdoor areas and neighbour buildings. This cognitive femtocell strategy will be compared with an alternative strategy where an operator deploys conventional femtocells and has to build additional base stations to meet the traffic demands. The business case analysis illustrates that there is a potential for cost savings when offloading the mobile network with cognitive femtocells when compared to the alternative strategy. It must be emphasized that the studied concept is innovative and that the business case period starts in 2017, hence, parameter assumptions are uncertain. Therefore, as the most important message of this work, sensitivity analysis is used to reveal the most critical aspects of the cognitive femtocell business case. It is found that the most critical parameters regarding the cognitive femtocell are the price for backhauling, the number of users supported and the coverage. Furthermore, an optimal coverage radius for the cognitive femtocell for lowest possible costs is found. Costs related to the fixed sensor network are found to be less critical since sensors are embedded in the cognitive femtocells. Sensitivity analysis is also presented for spectral efficiency, cognitive and conventional femtocell offloading gain, sensor density and price, customer density and price for base station site establishment.     

Agri‐environmental auctions for phosphorus load reduction: experiences from a Finnish pilot

We examine environmental auctions on working agricultural lands. We organized a discriminatory auction where farmers were asked to make bids on spreading gypsum on their fields to reduce phosphorus loads to surface waters. The parcel‐specific bids were ranked based on their load reduction–compensation ratios. To assess load reductions, we built an environmental benefit index (EBI) based on three factors: P‐status of the soil (phosphorus available for crops), field slope and location with respect to waterways. As the per tonne price of gypsum delivery from the factory was higher for small quantities, the auction format allowed bundling of field parcels to reduce transportation costs. We evaluate auction's ability to target the environmental (or abatement) measures to field parcels with the highest load reduction potential and analyse the economic efficiency of the auction by comparing the pilot auction with simulated bidding behaviour and with hypothetical flat rate payment schemes. The pilot auction targeted the environmental measures effectively. It was also more efficient than a flat rate payment, even when the flat rate scheme was combined with an EBI eligibility criterion.     

Climate in the making: Using Delphi for Finnish climate policy

In the assessment of the present state of climate change and the projection of its future development and impacts on human society, one of the core issues is the interaction between decision makers and the scientific community. Knowledge of the human and natural processes behind climatic change and of the risks involved should be communicated to policy makers in a form that is both comprehensible and useful in the formulation of policy measures. At the same time, the scientific community must meet the practical requirements and goals for research set by decision makers, even if this creates problems involving the validity of overly hasty answers to questions of paramount complexity. The purpose of this paper is to present some results of the study dealing with these questions and in particular to discuss the future scenarios produced in the course of that project.     

Exploration,exploitation, and financial performance: analysis of S&P 500 corporations

The literature suggests that established firms need to balance their exploration and exploitation activities in order to achieve superior performance. Yet, previous empirical research has modeled this balance as the interaction of orthogonal activities. In this study, we show that there is a trade‐off between exploration and exploitation and that the optimal balance between exploration and exploitation depends upon environmental conditions. Using a novel methodology to measure the relative exploration versus exploitation orientation, we find an inverted U‐shaped relationship between the relative share of explorative orientation and financial performance. This relationship is positively moderated by the R&D intensity of the industry in which the firm operates. Copyright © 2008 John Wiley & Sons, Ltd.     

Path dependence in net migration during the ICT boom and two other growth periods: the case of Finland, 1980-2013

This paper examines the path dependence of net migration surpluses and deficits by Finnish municipalities in the period of 33 years. Such spatial clustering revealed by spatial autocorrelation represents the spatial formations in which the development indicated by migration is statistically similar over the municipal borders. The results of survival analysis indicate that the chronic centripetal tendency of development generates higher path probabilities of a municipality staying in a surplus formation located in the main urban regions and an increased lock-in tendency compared with deficit formations in peripheries. Thus, the growth processes seem to translate into the self-reinforcing spatial formations of growth and decline in population, production and regional competitiveness suspended by economic downturns and recessions, and so this path dependence is cyclic and recurring, which means that paths constitute relatively short pulses. In the great surge of Information and Communication Technology industries in the 1990s, the spatial formations of migration were higher in volume and path-dependent, but against expectations, spatially less stable compared with more modest growth periods.     

Do networks of financial intermediaries help reduce local bias? Evidence from cross-border venture capital exits

Contributing to the literature on local bias and financial networks, we examine how direct and indirect network ties of financial intermediaries mitigate the effects of distance and preference for local investments. In our analysis of cross-border venture capital exits, we find that proximity within networks facilitates cross-border transactions, which suggests that network distance is an important dimension of distance in addition to its geographical and cultural dimensions. The results also suggest that network distance affects the reach and quality of mediated information: indirect ties to partners' partners, with their broad reach, facilitate the identification of investment opportunities, whereas direct ties, which have certification effects, facilitate quality assessment.     

Bequest Intentions of Forest Landowners: Theory and Empirical Evidence

This article studies in an overlapping generations forest economy the conditions under which money and/or timber bequests occur across generations, assuming the usual case of one–sided altruism. We assume nonindustrial landowners have preferences for consumption and for amenities from unharvested forest stock. Within this framework, we examine conditions under which landowners choose to leave timber or money bequests, and we show how taxation is important to these conditions. Empirical evidence from bequests decisions for a cross–section sample of nonindustrial landowners in Virginia is then used to investigate the hypotheses suggested by the model with regard to the motive to leave bequests. The results are broadly consistent with the theoretical findings.     

A Mixture Multiplicative Error Model for Realized Volatility

A multiplicative error model with time-varying parameters andan error term following a mixture of gamma distributions isintroduced. The model is fitted to the daily realized volatilityseries of deutschemark/dollar and yen/dollar returns and isshown to capture the conditional distribution of these variablesbetter than the commonly used autoregressive fractionally integratedmoving average model. The forecasting performance of the newmodel is found to be, in general, superior to that of the setof volatility models recently considered by Andersen et al.(2003, Econometrica 71, 579–625) for the same data.     

Test Procedures for Unit Roots in Time Series with Level Shifts at Unknown Time*

Two types of unit root tests which accommodate a structural level shift at a known point in time are extended to the situation where the break date is unknown. It is shown that for any estimator for the break date the tests have the same asymptotic distribution as the corresponding tests under the known break date assumption. Different estimators of the break date are compared in a Monte Carlo experiment and a recommendation for choosing the break date in small samples is given. Example series from the Nelson–Plosser data set are used to illustrate the performance of our tests.     

Optimal Design of Forest Taxation with Multiple-Use Characteristics of Forest Stands

The paper studies optimal forest taxation under uncertainty about future timber price when private forest owners value amenity services of forest stands and forest stands have public goods characteristics. It is assumed that preferences of forest owners can be described by a quasi-linear, intertemporal utility function which reflects risk aversion in terms of consumption and constant marginal utility in terms of amenity services. The comparative statics of current and future harvesting in terms of timber price risk, site productivity tax and yield tax are first developed. It is shown that, given the optimal site productivity tax, which is independent of the timber harvested and thus non-distortionary, it is desirable to introduce the yield tax at the margin; it both corrects externality due to the public goods characteristic of forest stands and serves as a social insurance device. The optimal yield tax is less than 100% and depends on the social value of forest stands, timber price risk and properties of compensated timber supply. In the general case the 'inverse elasticity rule – according to which the optimal yield tax is negatively related to the size of the substitution effects – may not hold. Under certainty, the desirability of the yield tax, given the optimal site productivity tax, depends only on the existence of public goods characteristic and is thus a pure Pigouvian tax.